App sidebar: some adjustments

- Cleanup
- fix disappearing appbar on changing appbar position
- may fix endless FC on changing appbar contents

Change-Id: I7667e60878c07b7c722dbd2bd5c2fd69bbbdda78
Fix bug with non-secure gesture lockscreen

Change-Id: I8d5f2be117f0609adeb1b8a3705bd9d3be5dc137